Machine tool



Jan. 24, 1961 c. HAMMOND MACHINE TOOL Filed May 7, 1959 INVENTOR, LEE 6.HAMMOND ATTOENEV United States Patent MACHINE TOOL Lee C. Hammond,Kalamazoo, Mich, assignor to Hammond Machinery Builders, Inc.,Kalamazoo, Micln, a corporation of Michigan Filed May 7, 1959, Ser. No.811,703

Claims. (Cl. 51-263) This invention relates to abrasive belt machines,and particularly to a structure for use therein which will enable thebelt to be run wet without unreasonable inconvenience or unpleasantnessto the operator.

In the application of a cooling and/or cutting oil, or other liquid, toan abrasive belt, it is and has been well known that a major problem inthis kind of operation is the spraying and splashing of the liquid ontothe operator and onto the floor around the machine. Particularly, theliquid often splashes from the belt onto the table and thence backagainst the hands or onto the clothes of the operator or onto the floor.Further, a large quantity of such liquid on the belt is often removedfrom the belt by the workpiece but without appreciably diminishing itsvelocity and hence travels away from the belt and against the hands oronto the clothes of the operator or onto the floor. Many kinds and typesof shields have been devised and are well known to the trade but none ofthem, insofar as I am aware, has been able to solve the problem. Infact, in many cases where wet grinding has been used, the operator hashad to wear rubber gloves and an apron, and has often in addition had tostand on a rack, in order to avoid excessive subjection to cooling and/or cutting liquid. Therefore, while wet grinding has been long known, isdesirable in many cases and essential in many other cases, it has alwaysbeen inconvenient and'unpleasant for the operators because of theirsubjection to constant splashing of the cooling and/or cutting liquid asabove described.

A further problem in the use of an abrasive belt consists in the longrecognized fact that a more rapid and at the same time a better,grinding operation can be carried out if a much larger volume of cuttingand/or cooling liquid is used than is now usual. However, withconventional equipment, it is virtually impossible to use such a largevolume of liquid inasmuch as the amount thereof which would be splashedback and against the operator would render such use prohibitive. thepresent equipment makes it necessary to hold the volume of such liquidat such a level that the amount splashing back against the operator canbe tolerated. Thus, the amount supplied to the work is considerably lessthan would be useful. Accordingly, it is desirable to provide apparatuswhich will make possible the use of a much larger volume of coolingand/or cutting liquid than is possible in present conventional practicewithout simultaneously raising the amount splashing back against theoperator to an intolerable quantity.

Accordingly, the objects of the invention include:

1) to provide a device useable with an abrasive belt type of grindingmachine for preventing the cutting and/or cooling liquid used therewith,even though used in large volumes, from being directed in anyappreciable amount against the hands and clothes of the operator or onthe floor;

(2) to provide an attachment for a belt grinding machine which will bothdirect cutting and/ or cooling liquid Therefore, a

against the belt and will also protect the operator from liquid beingthrown against his hands and clothes and will keep the floor dry aroundthe machine;

(3) to provide a device, as aforesaid, which will permit an extremelylarge volume of cutting and/or cooling liquid to be discharged againstthe belt and yet without any appreciable amount thereof striking theoperator or the floor;

(4) to provide a device, as aforesaid, which will in no way restrict theoperators ability to move the work toward and away from the belt or backand forth across the face of the belt;

(5) to provide a device, as aforesaid, which will provide a minimum ofrestriction to the operators visual control over the work. and, to theextent that such visual restriction is unavoidable to confine it tocircumstances where it can be tolerated;

(6) to provide a device, as aforesaid, which can be readily attached toa wide variety of platen belt grinding machines and which can be easilymodified to fit a still wider variety of machines;

(7) to provide a device, as aforesaid, in which the liquid dispensingunit and the operator protecting unit are associated together and may beattached to the grinding machine by a single bracket and both will beadjustable up or down at the same time with this single bracket;

(8) to provide a device, as aforesaid, which will prevent liquid whichis deflected off the belt and strikes the table from rebounding againstthe operator or onto the floor;

(9) to provide means which will prevent liquid which is deflected fromthe belt by the workpiece from striking the operator or going onto thefloor;

(10) to provide a device, as aforesaid, which will be of suflicientsimplicity that its cost is negligible as compared to the cost of theentire machine; and

(11) to provide a device, as aforesaid, which can be supplied as a partof a new machine or which may be easily attached to an old machine.

Other objects and purposes of the invention will become apparent topersons acquainted with devices of the general type upon a reading ofthe following description and inspection of the accompanying drawings.

In the drawings:

Figure l is a front fragmentary view showing the table and the portionof the belt grinding machine above the table, said machine being fittedwith an attachment embodying the invention.

Figure 2 is a fragmentary view of the leftward side of the machine shownin Figure 1 and presented on a smaller scale than Figure 1.

Figure 3 is a section taken on the line IlI-III of Figure 1 andpresented on a larger scale than that used in Figure 1.

Figure 4 is a section taken on the line IVIV of Figure 3.

General description In general, the invention consists of placing aperforated tube on a bracket and arranging the bracket to hold the tubeshortly above the normal position of the work. The axes of theperforation are arranged at from about 45 to about 60 with respect tothe surface of the belt. Liquid is supplied to said tube for dischargeagainst the belt at a relatively moderate pressure, so that the liquidlies against said belt and does not rebound appreciably therefrom. Meansare provided for ready cleaning of the perforations. The tube is alsoutilized for the support of a flexible and preferably transparentcurtain which hangs from the tube to a point in contact with the workand extending across, and preferably slightly beyond, the full width ofthe abrasive belt. The curtain being flexible the work can be pushedalong the table through and under the curtain into contact with thebelt, PPQW from S d to id ere n if esir d. and he urteia will soai r itst h w r sutfic entl l e that no appreciable amount of liquid will bepermitted to strike the operators hands or clothes or will escape ontothe floor. Further, where appropriate, the curtain can be cut to fit agiven workpiece'as closely as desired.

Detailed description In the description of a preferred embodiment of theinvention, certain terminology will be used for reference purposes whichwill be recognized solely as descriptive and having no limitingsignificance. Thus, the terms upward and downward, and derivativesthereof and words of similar import, will refer to the apparatus when ina normal position of operation and as shown in the drawings, namely,with the working surface of the belt positioned substantially verticallyand running downwardly. The terms rightward and leftward and derivativesthereof and words of similar import, will refer to the rightward andleftward side of the machine viewed by the operator when facing it in anormal position of use, namely, the position of the apparatus asappearing in Figure 1. The terms inward and outward and derivativesthereof and words of similar import will refer to directionstoward andaway from the geometric center or the apparatus. The terms forward"'andrearward and derivatives thereof and words of other similar import willrefer to directions perpendicularly toward or away from the workingsurface of the belt, namely, to directions in which the work moves onthe table as it moves toward and away from working contact with thebelt.

In the drawings there is shown fragmentarily a conventional beltgrinding machine, which may be of any of several types, such as thatshown in US. Patent No. 2,612,007 or in Robischung application SerialNo. 738,- 869, now US. Patent No. 2,900,766. In this machine, anabrasive belt 1 of conventional size and type is supported around a pairof pulleys, of which one appears at 2, and is covered by a suitable hoodor shield 3. Suitable power means, not shown, are provided to rotativelydrive one of said pulleys in a conventional manner. A table 4 isprovided for support of the workpiece and, if desired, said table may bevertically adjustable around an axis lying in or adjacent to the workingsurface of the belt in any convenient manner, such as by the slot andbolt arrangement generally indicated at 6. A platen 7 (Figure 3) isprovided against which the belt 1 runs to provide suitable backing forsaid belt as a workpiece W is pressed against it.

A bracket 8 contains a slot 9 through which extend suitable wing-studs11 and 12 by which said bracket is adjustably fastened to the hood 3. Atthe lower end of said bracket 8 there is located a header 13 extendingsidewardly therefrom and across the face of the abrasive belt 1. Saidheader contains a bore 14 closed at one end by a suitable plug 14a, andhaving a series of small drilled openings 16 by which cooling and/ orcutting liquid introduced into said bore 17 under pressure may bedischarged against the face of the abrasive belt 1. A pair of furtherbores 17 and 18 are provided for receiving liquid to be introduced intothe bore 14 and for etfecting introduction thereof into the center ofthe bore 14. A threaded nipple is threaded into the leftward end of thebore 17, receives the lower end of the bracket 8 and a nut 15a isscrewed onto the nipple 15 for holding the bracket 8 and the header 13tightly together.

Liquid is supplied to said header through a suitable conduit 19, whichis preferably provided with a manually adjustable valve 20 and issuitably threaded onto the leftward end of the nipple 15.

i A flexible sheet 21, which is desirably also transparent, is grippedbetween a'pair of strips 22 and 23 and is held against the lower side ofthe header 13 by a series of screws of which one appears at 24. Thecurtain is advantageously made from any suitable transparent andflexible plastic, such as cellulose acetate, Mylar, etc., but it may bemade of neoprene, or similar, within the purposes of the invention andwithin its advantages. Said curtain 21 extends across the full width ofthe belt 1 and preferably, as appearing in Figure 1, also extends asubstantial distance beyond said belt on both sides thereof. Saidcurtain 21 extends downwardly a distance sufficient that it firmly liesagainst the upper surface of the workpiece W.

While the exact angle at which said discharge openings 16 dischargeagainst said abrasive belt may be varied to suit varying conditions, itwill normally be found preferable that said openings are arranged at notmore than about 60 of angle with respect to the belt, and an angle ofabout 45 will be better if other conditions permit. With the axes of thedischarge openings making with respect to the face of the belt an angleof between about 45 and about 60, the liquid discharged against saidbelt will lie on said belt without any material portion rebounding awaytherefrom and thus the maximum amount becomes available for cooling ofthe grinding surface as well as that portion of the workpieceimmediately behind the surface being ground. Further, in this manner thecontrol thereof is rendered most effective to minimize splashing of saidliquid in the direction of the workman or onto the floor. At the sametime, th e pressure at which the liquid is supplied to said openingsshould be of only moderate nature. More specifically, it should beenough to direct the entirety of the streams through the air layertravelling with the belt and thence to direct the streams against thebelt, but small enough that there will be little tendency for liquid torebound away from the belt. It will be recognized that the specificpressure will vary according to the size of the jet openings as comparedwith the volume of liquid supplied and accordingly the pressure selectedfor a given installation can be defined only in terms of pressurerequired to provide the performance above described.

Where a number of identical workpieces of a regular shape are beinghandled, it will be preferable to cut the lower edge of the curtain tomatch the shape of the workpiece so that one portion of the curtain willtit closely to the workpiece and other portions of the curtain will lieclosely against the table. Inasmuch as very little of the liquid willsplash onto the table when the workpiece is out of working position, therelatively small amount of liquid which may come through such cut-outportion when the workpiece is removed and before another workpiece isinserted, will be inconsequential.

Operation The device as described may be attached to practically anystandard abrasive belt grinder merely by providing openings to receivethe wing studs 11 and 12., together with providing a suitable connectionfor the conduit 19.

With the belt then running in a normal manner, an adequate supply ofcutting and/or cooling liquid may be introduced from the conduit 19 intothe bore 17 and thence by way of passageways 18 and 14 through theopenings 16 against said belt. The curtain 21 will protect the workmanfrom liquid splashing from the belt onto the table and thence back tothe workman as well as from liquid being substantially peeled from thebelt onto and by the workpiece and thence directed back against theworkman. Thus, by protection of the workman in this manner, a muchlarger volume of cooling and/or cutting liquid may be used than wouldotherwise be possible and this permits a more rapid and cooler grindingoperation than is possible in present practice.

Thus; actual tests have shown that with the much larger amount ofcutting and/ or cooling liquid which it becomes possible to use by thedevice of the present invention, it is possible to hold a workpiececontinuously against the belt for much longer periods of time than hasbeen possible in previous practice without developing excessive heattherein, said excessive heat being undesirable both because of itsunpleasant reaction on the operators hands and because of its destroyingthe otherwise carefully regulated and controlled crystalline structureof the material comprising the workpiece.

By causing the curtain 21 to be of highly flexible material, it will berecognized that said curtain will arrange itself firmly against aworkpiece of any ordinary shape so that regardless of the size and shapeof the workpiece, very little of the cooling and/ or cutting liquid willsplash past the curtain onto the workman and this will be true both whenthe workpiece is forwardly against the abrasive belt in cutting positionas well as when the workpiece is retracted either a limited distance orhas been fully withdrawn from the machine.

It is recognized that there will be a slight inconvenience on the partof the workman in the initial stages of using this device by reason ofthe curtain 21 becoming covered with liquid and rendering it difficultfor the workman to clearly see the Work. However, a properly directedlight helps in this respect and most workmen will become accustomed tothis in a short period of time and will be able to handle the apparatussatisfactory by combination of vision and feel and the majority ofworkmen will find the quality of the article produced, together with theconvenience of being free from the splashing of the liquid being usedfor cooling and/or cutting purposes, far outweigh the disadvantages ofsomewhat limited visual control over the workpiece.

As a normal working operation progresses, the inevitable accumulation ofdebris in the liquid will eventually tend to obstruct some of thedischarge openings 16. This cannot be tolerated to any great extentsince it will destroy the purpose of the liquid dispensing apparatus. Inthe present construction, however, this situation is readily cured as itarises merely by removing the plug 14a and cleaning out the tube 14 withany convenient instrument, such as a cylindrically shaped brush.

While a specific embodiment of the invention has been utilized forillustrative purposes, it will be recognized that the invention may alsobe expressed in a variety of other specific embodiments and accordinglythe hereinafter appended claims will be interpreted to cover such otherembodiments unless said claims by their own terms expressly requireotherwise.

I claim:

1. In a device for supplying cooling and/or cutting liquid to anabrasive belt and for simultaneously protecting the user from excessivesplash of said liquid, the combination comprising: a conduit and meanssupporting same across and spaced from the face of said abrasive belt, aplurality of discharge openings through the side of said conduit openingin the general direction of the said abrasive belt; a work-supportingtable adjacent said belt below said conduit; a flexible curtainextending from said conduit into close proximity with said table, saidcurtain being of width at least equal to that of the abrasive belt;means afiixing the upper edge of said curtain to said conduit, theremainder of said curtain being unsupported so that it hangs downwardlyfrom said conduit and the lower end thereof is free to flex toward saidbelt whereby a workpiece may be pushed along said table under saidcurtain and said curtain will arrange itself sufliciently snugly againstsaid workpiece that a minimum of liquid discharged from said conduit:will pass back either by traveling along said workpiece or by splashingagainst said table toward and against the operator.

2. An attachment for use with an abrasive belt machine having awork-supporting table, comprising in combination: a header containing aconduit extending substantially the full length thereof and having aplurality of discharge openings through the side thereof; a bracket forsupporting said header in a selected position on said machine and withthe outlet ends of said discharge openings arranged in a line parallelwith and spaced from the working surface of the abrasive belt; aflexible and transparent curtain and clamp means aflixing the upper edgeof said curtain onto said header, the remainder of said curtain beingunsupported so that it may hang downwardly from said header to alocation adjacent the upper surface of said table but spaced therefrom adistance not greater than the vertical dimension of the workpiece, thelower end of said curtain being free toflex whereby a workpiece may bepushed under said curtain and in contract therewith into contact withsaid abrasive belt.

3. The device defined in claim 2 wherein said discharge openings aredirected at an angle of not more than about 60 with respect to thesurface of said belt.

4. The device defined in claim 2 wherein the lower edge of the curtainis cut to match and fit snugly around the upper and side surfaces of theworkpiece.

5. A grinding machine comprising a substantially vertically arranged,movable abrasive belt; a work support located adjacent a course of saidbelt; a conduit mounted above said work support for directing liquidagainst said course of said belt; a flexible sheet supported along theupper end thereof adjacent said conduit and extending downwardlysubstantially to said work support in front of said course of said belt,the lower end of said sheet being free to flex toward said belt wherebya workpiece supported on said work support may be moved into engagementwith said course of said belt and the lower end of said sheet will flexto the extent required to permit such movement, said sheet serving as asplash shield to confine the liquid in the zone between said course ofsaid belt and said sheet.

References Cited in the file of this patent UNITED STATES PATENTS986,170 Heady Mar. 7, 1911 2,228,386 Burns Jan. 14, 1941 2,292,229Krueger Aug. 4, 1942 2,550,899 Zsamboky May 1, 1951 2,562,229 Bell Ju'y31, 1951 2,757,487 Coburn Aug. 7, 1956

